Fixing Random Restarts in LX570: Random Power Failure / Shut off / Restarts Dash & Infotainment System also getting ' Check 4 Wheel AHC System' Error

[That 2011 LX570]

This thread is intended for future reference, as I’ve discovered that this issue is quite common in older LX570 models.

The problem began after I had the ABS system repaired, specifically the link rod connecting the brake pedal to the ABS unit beneath the driver-side instrument cluster. After pressing the brake too hard to achieve proper braking, I decided to address the issue. The experienced technician replaced the link rod, and the brakes improved. However, from that day forward, my vehicle started to randomly restart while driving, particularly when I applied the brakes lightly. This caused the instrument cluster and infotainment system to restart unexpectedly.
I returned to the same workshop, but the technician was baffled since I couldn’t replicate the error. I visited several other workshops without success. Eventually, I decided to conduct my own research, particularly on IH8MUD.COM.
I compiled a list of checkpoints as follows:

1. Cleaned the battery terminals, which had some corrosion/mould, using WD-40.
2. Checked all ground points, which were fine.
3. Went under the instrument cluster and ensured all harness clips were securely connected.
4. Inspected all fuses, which were also intact.
5. Most importantly, I noticed some harnesses connected to the brake pedal and other components were loose because the technician hadn’t 'Clipped' them properly to prevent their movement during the ride, so I fixed those.

And just like that, the problem was resolved!

While I’m not jumping to conclusions, I strongly believe the issue stemmed from the loose harnesses, which caused intermittent connections when braking due to inertia.
If anyone else encounters a similar issue, feel free to follow the steps I took!

 

[ryanCA]

geez

stay away from that “technician “

 

[bloc]

Random bit of knowledge: most manufacturers design their wiring harness clips to make an audible "click" when sufficiently engaged, for this exact reason.

 

[Eman87]

This is happening to my car as well. It started with the screen turning on and off, and now more recently my dash as well, all while running the car. As I sat idle, I noticed while it's all flickering, the engine seems to lose power. I had the battery cleaned up from corrosion and left a charger run all night, and car all warmed up before I drove off today. I left the the auto height adjustment to normal and locked since last time it triggered the flickering as it tried to move the height from low to high. Car was on for about 30 mins, drove 10kms or so, and dash and screen flickered again.
So now I'm thinking I'll check the alternator connection and probably replace the battery since it's a 3 yr old Canadian Tire battery.
Any other suggestions is appreciated. Thanks

 

[CanadianRockyCruiser]

1.) and 5.) sound like the common culprits. The areas that people mess with tend to be the problem.

 

[Eman87]

Update: I had my 3yr.old battery checked at Canadian Tire and the associate said it's "ok, but on the verge of needing replacement". This was checked even after trickled charge the night before. So I ended up just replacing the battery. It's been a day now and so far no issues.